024 KAMIIA' h. — SCAKAli.l'IDxE. 



IX. At.v>ntus Thirokl. 18B7. (Gv., 'Svitliout a fetter.") 



►S^iiciU, siciKb-r, l)lackisli insects i-cseiiibliuy Aijlnxliiis, ])ut usu- 

 ally smaller and more elongate. The head is convex, not tubercu- 

 late; eyes usually concealed; hind tibia^ simple, straioht, the outer 

 a])ieal angle more prolonged than in Apliodius and often ending in 

 a spine. The strioe of elytra often ai)pear more coarsely punctured 

 than they really are, due to the si ties of the intervals l)eing crenate, 

 this crenation being entirely indei)endeut of tlie punctures of the 

 striiP, which are fine and distant. The "accessory spinule" of the 

 hind tibias mentioned iri the key below is a prolongation of the 

 apical margin on the under side near the spurs. Seven species have 

 been talcen in Indiana, while two others ]ierhaps occur. 



KEY TO INDIANA SPECIES OF AT.ENIUS. 



a. Clypeus feebly emarginate at midfUe, broadly ronuded on eacli side, 

 never dentate nor subangulate. 

 J). Oiiaijue species; thorax withont basal marginal line; bead densely 

 and finely i)nnctured. not wrinkled; hind tibire withont accessory 

 spinule. 

 c. Elytral intervals flat. 1743. imbricatus. 



cc. Elytral intervals alternately more elevated. 1744. alternatus. 

 hi). Shining species; thorax with basal marginal line. 

 fl. Hind tibiae withont accessory spinnle. 



e. Elytra oblong-oval, base slightly emarginate; form rather ro- 

 bust ; thorax unequally and irregularly punctured. ovatulus. 

 ce. Elytra elongate, parallel, base truncate ; form slender, elongate ; 

 thorax evenly and densely imnctured. 1745. gracius. 



(Id. Hind tibiae with accessory spinule. 



/. Clypeus finely punctured without traces of wrinkles ; occiput 

 with coarse punctures. strigatus. 



//. Clypeus more or less wrinkled and coarsely punctured; thorax 

 with coarse and fine inmctures intermingled. 1746. cognatus. 

 (/(/. ('lypeus sul)angulate, or sometimes denticulate each side of the median 

 emarginatiou. 

 g. Thorax nearly smooth in front, coarsely and rather sparsely punc- 

 tured behind the middle, more densely at sides; intervals of elytra 

 convex ; marginal line of hind femur deep and entire. 



1747. LECONTET. 



.'///. Thorax nearly evenly punctured from base to apex; marginal line of 



hind femur very short or absent. 



/). Piceous species; first joint of hind tarsus as long as tiie long spur; 



thorax densely imnctured. 3748. abditus. 



///(. li(Hldish-bi-o\vn ; first joint of hind tarsus shorter than the long 



spur; tlidrax rogiil.irlN not densely |innctin'<^d, the punctures a 



little finer in fnmt. 1749. inops. 



